Adducts of alkyl fumarates and aliphatic olefinic aldehydes



ADDUC'IS OF ALKYL FUMARATES AND ALIPHATIC OLEFINIC ALDEHYDES Joachim Dazzi, Dayton, Ohio, assignor to Monsanto Chemical Company, St. Louis, Mo., a corporation of Delaware No Drawing. Application April 18, 1956 Serial No. 578,887

4 Claims. (Cl. 260-483) This invention relates to aldehyde-esters and more particularly provides new and valuable dicarboxylates, a process of producing the same and vinyl chloride polymers plasticized with said new compounds.

An object of the invention is the provision of new and useful unsaturated aldehydo-esters. Another object of the invention is the preparation of useful addition prodnets of certain olefinic aldehydes and certain esters of fumaric acid. A further object of the invention is to provide for the synthetic resins and plastics, rubber and textile industries, a new class of stable, viscous compounds of high carboxylate content.

These and other objects hereinafter disclosed are provided by the following invention wherein unsaturated aldehyde esters are prepared by the addition reaction of aliphatic mono-olefinic aldehydes of from 5 to 18 carbon atoms and an alkyl fumarate. The reaction is one of simple addition in which one mole of the aldehyde adds to one mole of the fumarate substantially according to the scheme:

OHO.,R YOOCIHJH OHC.R.OHCOOY CH.GOOY CHQCOOYI which R is a bivalent alkenylene radical of from 4 to 17 carbon atoms and Y and Y are alkyl radicals of from 1 to 8 carbon atoms.

Although it is believed that the 1,2-dicarboxyethyl radical is attached at the carbon atom which is adjacent to that which bears the olefinic double bond of the aldehyde, the exact position at which the dicarboxyethyl radical is present is not exactly known. However, it is known that an aldehydo group is present in the addition product and that the addition takes place at a saturated carbon atom and not at the olefinic double 'bond of the unsaturated aldehyde.

Alkyl fumarates which may be employed in preparing the present adducts are the simple or mixed alkyl fumarates such as methyl, ethyl, n-propyl, isopropyl, butyl, isoamyl, n-hexyl, n-octyl, 2-ethylhexyl fumarate, ethyl methyl fumarate, ethyl n-propyl fumarate, isopropyl n-octyl fumarate, etc.

Aliphatic mono-olefinic aldehydes of from 5 to 18 carbon atoms which add with the alkyl fumarates to yield the present adducts are, for example, a-propylacrolein, tiglic aldehyde, 2-hexenal, Z-decenal, 2-ethyl-2-hexenal, 2-dodecenal, 2-methyl-2-pentenal, octadecenal, etc.

I Reaction of the unsaturated aldehyde with the alkyl fumarate to form the 1:1 addition products takes place readily by heating the aldehyde with the fumarate in the presence or absence of an inert diluent or solvent at ordinary or super-atmospheric pressure. When operating at atmospheric pressure temperatures of from, say, ZOO-300 C. and preferably of from 210--280 C. are used. Usually the lower alkyl fumarates are more reactive than the higher alkyl fumarates. In view of the elfect of the reaction conditions and nature of the fumarate and of the adehyde upon the extent to which the fumarate participates in the reaction, it is recommended 2,887,507 Patented May 19, 1959 ice that for each initial run optimum operating conditions be experimentally determined.

Since the alkyl fumarates employed in the present reaction are generally miscible with aldehydes under the reaction conditions used, no extraneous solvent or diluent need generally be employed. For successful reaction a diluent may or may not be present. Reaction is advantageously effected in an inert atmosphere, e.g., in nitro gen or in carbon dioxide; and for good yields of product within comparatively short reaction times operation in a closed vessel, i.e., at pressures above atmospheric, is recommended.

In practice, the aldehyde and the fumarate are mixed in a reaction vessel and the mixture is heated, say, at the refluxing temperature thereof, for a time of, say, a few hours to a day. Completion of the reaction may be noted by cessation in change of refractive index upon continued heating.

The present 1:1 olefinic aldehyde-alkyl fumarate adducts are stable, viscous liquids. They are valuable for a variety of commercial and technical uses, e.g., as lubricant adjuvants, as intermediates for the preparation of resins and varnishes, as moisture-proofing agents, etc: They are particularly valuable as plasticizers for polyvinyl chloride and copolymers of at least 70% by weight of vinyl chloride and up to 30% by weight of an unsaturated monomer copolymerizable therewith, for example, vinyl aceate, vinylidene chloride, etc. The present olefinic aldehydo-esters impart great flexibility to vinyl chloride polymers at low temperatures; they are compatible with such polymers and show no exudation of plasticizer even at plasticizer content of up to 50%. Although the quantity of plasticizer will depend upon the particular polymer to be plasticized and upon its Example 1 A mixture consisting of g. (1.35 moles) of 2-ethy1- 2-hexenal, 620 g. (2.7 moles) of butyl fumarate and 1 g. of di-tert-butylcatechol (as polymerization inhibitor) was heated in a rocking autoclave at a temperature of 220 C. until the refractive index of the reaction mixture had risen from an initial n 1.4460 to 1.4560. Distillation of the resulting reaction mixture gave 44 g. of (I) a fraction B.P. 150-70 C./ 1.8 mm. and as residue 476 g. of (II) a viscous material boiling above 180 C. The following analytical data for both (I) and (II) show these materials to be substantially the pure 1:1 2-ethyl- Z-heXenal-butyl fumarate adducts, since the calculated value for said 1:1 adduct (C H O agrees with the found carbon and hydrogen values of (I) and (H).

A mixture consisting of 423 g. (3.4 moles) of 2-etl1yl- 2-hexenal, 388 g. (1.7 moles) of butyl fumarate and 1 g. of di-tert-butylcatechol (as polymerization inhibitor) was heated for 12 hours at a temperature of 220 C. in a rocking autoclave. During the heating period the refractive index of the reaction mixture rose from n 1.4464 to 1.4585. Distillation of the resulting reaction fractions: 142 g. of (I), .B.P.

I I residue 108.5 g. of adduct n 1.4752hna1y'zihg- 68.08% carbon and 9.36% 1 hydrogen. I Since the calculated values. for 1:1 'Z ethyLheXenaLbutyl :r'esidue'consist, ot the 1:11, adduct essentially. I I I I ExarIripleS I I I fumarate adduct II are 67.8% C,'9'.6% 'H and Sap. Eq.=l77, fractions' (I)-''( I'II) andthe' yv P 0 P l/V h id a d 401 by. I f The, E s icized; Poly inyl halide compositions of the weight of the, 2'ethyl-2-hexenal-butyl tumarate adduct {of Exarnple-2 fraction (111)) were mixed on; milling I rolls to a homogenous blend; Du ring the milling. there was observed, substantially no turning and discoloration;

I I present invention have good thermal. stability; however, I I I: for many purposes-it may be advantageous. to use known I i 1 3 A molded sheet of. the I mixture was. clear and trans. I Z

:method gave a value. of minus, 19.6" C. When:sub-

I jected to heat at atemperature :of;325 F, tora p er iod I of I minutes the clarity and color of the rnolded. prode I I I nct was substantiallyunchanged. Tests of the water re-,

. sistance properties of the plas ticized material by im- I I mersing the molded specimen for 24 hours'inwa ter gave I I I a water absorption value of 0.66% and 'a solids loss value I of the adduct ofExample '2 Kerosene. resistance of the molded. test 'specimen' (fraction '(III)) was deter-.

mined as follows:- I I I I I I I A 2 diameter, '40 mi1' I 6. even for a 3-hour conditioning pcriodtoeliminate water, then 'coole'd 'aind weighed I The conditionedsammoved from the kerosene; 5 blotted I my and suspended in a force-draft 80 C. oven for 4 hours. The sample was then cooled and weighed. The percent loss in weight thus determined, i.e., the kerosene extraction value, was found to be 2.3%.

Example 4 Evaluation of the residue (II) of Example 2 using the procedures described in Example 3, gave a low temperature flexibility value of minus 14.5 C., a solids loss of 0.09%, a water-absorption value of 0.49% and a kerosene extraction value of 2.6%

Adducts of other alkyl fumarates and of other olefinic aldehydes likewise possess very good plasticizing properties for vinyl chloride polymers. Thus, by employing parts by weight of the adduct of hexenealdehyde, of tiglic aldehyde or of 2-dodecenal and n-octyl fumarate, or isopropyl methyl fumarate with 60 parts by Weight of polyvinyl chloride or with 60 parts by Weight of a vinyl chloride-vinyl acetate copolymer known to the trade as Vinylite" there may be obtained clear, colorless compositions of very good flexibility and stability.

While the above examples show only compositions in which the ratio of plasticizer to polymer content is 40:60, this ratio being employed in order to get comparable efiiciencies, the content of ester to polyvinyl chloride may be widely varied, depending upon the properties dedisc was suspended in a 5 I in which'R is an; alkenylene radical of from 4 to 17 car are alleyl radicals of'from ,1, I 1 I I Q I I to 8 carbon atoms. I I ple was then immersed in 400 ml;. of kerosene for a pe I I .riod of 24 hours, at 27 C. The sample was then rewith polyvinyl 'chlorideover wide ranges of concentra- I tions, up toSO-percentof .adductbased on the total weight of the-plasticizecl composition yieldingdesirable prc ducts. I

Although the invention, has .been'described 'particu- I I ,larly with referenceto the usc of the present adducts as I plasticizersfor polyvinyl chloride, these adducts are, ad- I vantageously employed also as plasticizers for copoly- I .mers'of vinyl chloride, fol-example, the copolymers of i vinyl chloride with vinyl acetate, vinylidene chloride, Y

etc. Preferably, such copolymers have a high, vinyl chlo- I ride content,i.e., a vinyl chloride content 01 at least '70 percent by weight of vinyl chloride: and up to 30 per-. cent by weightof the copolymerizable monomer.

stabilizers in the. plasticized compositions. Inasmuch as I the present addu'cts are substantially unreacltige with the. I i I I I I I I I I I commercially available heat and lightstab 'ers which; i pgrentfandisubsIItafltrallyt c9l r 1S $g ng f ti jlIe rTIollded I 2 am Icammonly cmployed Iwithpalyvinyl, m Oreo, I I

eet or 0w empfira are an 'y I a as I erg 3 polymers thereof, the presenceof such materials in the I plasticized products does not impair the valuable prop-fl i I I I 1 I erties ofthe adducts. The present 'adduct's are of gen- I er al utility in softening vinyl chloride polymers.- I They 1 may be used as the only plasticizer components in a I I I I compounded vinyl chloride polymer or they may he used: I

- I l. Anadduct having the formula m onon onooory ontooo'r' I blimatoms and Y' and Y 321 The'adduct defined in; claim 1, :further character,-

is the addition product of 2-ethylhexenal and butyl fumarate.

3. The method which comprises heating an aliphatic monoolefinic aldehyde of from 5 to 18 carbon atoms with an alkyl fumarate having from 1 to 8 carbon atoms in the alkyl radical and recovering from the resulting reaction product an adduct of the formula oHo.R.cHoooY H COOY in which R is an alkenylene radical of from 4 to 17 carbon atoms and Y and Y' are alkyl radicals of from 1 to 8 carbon atoms.

4. The method which comprises heating 2-ethyl-2- hexenal with butyl fumarate and recovering from the resulting reaction product an adduct in which one mole of the 2-ethyl-2-hexenal is combined with one mole of the butyl fumarate.

References Cited in the file of this patent UNITED STATES PATENTS 2,598,636 Dazzi May 27, 1952 2,610,203 Hagemeyer et al. Sept. 9, 1952 2,665,304 Patrick Jan. 5, 1954 2,709,691 Dazzi May 31, 1955 iized in that R is an ethyl-substituted .pentenylene radical: I I I I and Yand Y are butyl radicals and in that adduct 

1. AN ADDUCT HAVING THE FORMULA 